In recent years, friction rock stabilizers, particularly those sold under the trademark "Split Set", by Ingersoll-Rand Equipment Corporation, have become quite popular for stabilizing or anchoring metal mine roofs. These stabilizers are manufactured in the form of split tubes, varying in length from three feet to eight feet, and are exemplified by the disclosure of U.S. Pat. No. 3,922,867, issued Dec. 2, 1975, to James J. Scott, for "Friction Rock Stabilizer". Pneumatic insertion tools like jackdrills and stopers are frequently used for installation of these stabilizers.
Jackdrills and stopers have a minimum working height of about five feet. Accordingly, in low headroom mines, friction rock stabilizers cannot be installed, directly, with standard jackdrills or stopers. A special tool or accessory is required which, when used with conventional drivers (such as jackdrills or stopers), will enable the insertion of the stabilizers into low headroom mine roofs or the like.
Examples of a special accessory for use in low headroom situations are found in U.S. Pat. Nos. 4,327,806; 4,530,409; 4,589,501. These devices provide an offset driver stub that is mountable to one side of the rock drill, the accessory being engaged in the chuck of the rock drill and being angularly adjustable for properly aligning the stabilizer relative to the receiving hole. However, the use of such a tool requires the maintenance of an additional separable accessory for the rock drill. Like all separable tools, such accessory devices are subject to loss and damage, particularly within the difficult working environments typically encountered within a mine. Its utilization also complicates mining procedures by introducing an additional tool change. One using such an accessory must first mount it within the chuck of the rock drill. Then the user must substitute a conventional stabilizer driver to complete the insertion of the stabilizer, since the longitudinal offset of the accessory inherently limits the total insertion capability of the accessory.
A rigid gooseneck typically interconnects the rock drill to a supporting jack leg that is extendible longitudinally to properly support the rock drill and move it toward the working face of a mine. The pivot axis of the rock drill relative to the gooseneck is offset to one side of the longitudinal axis of the jack leg, assuring free pivotal movement of the rock drill at any elevational position of the jack leg.
One object of this invention is to provide an integral driver on the gooseneck for engaging and initially inserting friction rock stabilizers without the need of a separable accessory tool. The improved gooseneck permits initial insertion of the friction rock stabilizer by use of the pneumatic jack leg in combination with the vibrational movement imparted to the gooseneck by operation of the attached rock drill. Final insertion can then be readily accomplished by use of a conventional driver tool mounted within the chuck of the rock drill. Only one tool change is required for complete insertion of a stabilizer, rather than two.